[Effects and mechanisms of Herba dendrobii on rats with stomach-heat syndrome]

To observe the effects of Herba dendrobii on rats with stomach-heat syndrome and to explore the mechanisms.

Rats were fed with decoction of Rhizoma Zingiberis for 15 continuous days to induce the model of stomach-heat syndrome. After modeling, Herba Dendrobii (HD) decoction were given (in the doses of 1.5, 0.75 g x kg(-1) respectively) for 10 days. After treatment, amount of the daily diet, volume and absorbance of urine, pellet number and moistness of excrement, color and coating degree of tongue were recorded; the body thermal effects were detected with thermal texture maps (TTM) system; the biochemical indexes of blood reflecting the physiological function of stomach, including thromboxaneB2 (TXB2), 6-keto-prostaglandin F1alpha(6-keto-PGF1alpha), motilin (MTL), gastrin (Gas), somatostation (SS), interleukin-4 (IL-4) and interleukin-8 (IL-8) were measured by radio immunoassay; and the histological changes of gastric mucosa were observed by hematoxylin-eosin (HE) stain.

The model rat had yellow coating and red tongues (P < 0.05). The amount of daily diet were increased (over 10%), urine volume and excrement pellet number were decreased (over 10%). The their urine color became deep (P < 0.01) and their excrement became dry. The temperatures in head, neck, left fore-armpit, chest, up-abdomen, mid-abdomen of the model rats were raised up (difference > 0.5 degrees C or difference > 1.0 degree C ). The content of 6-keto-PGF1alpha in blood of model rats decreased evidently (P < 0.01), and the contents of MTL, Gas and IL-8 increased conspicuously (P < 0.01). The histological changes of gastric mucosa in the model rats were as follows: diffuse congestion, infiltration of neutrophil, less secretion, decrease of the number of chief and parietal cells, etc (P < 0. 05 or P < 0.01). After treatment with HD, except the daily food weight, the temperatures in head, neck and chest, the content of MTL and the number of chief cells, the other indexes observed above were improved noticeably (difference > 0.5 RC or difference > 1.0 degree C, P < 0.05 or P < 0.01).

The reason why HD relieves the general symptom and sign the gastric mucosa of rats with stomach-heat syndrome is that HD can increase 6-keto-PGF1alpha and decrease IL-8, Gas, TXB2 in their blood.